1. Field of the Invention
This invention relates to microprocessors and more particularly to mechanisms and techniques for dynamically managing the internal clock speed of a microprocessor to enhance performance while preventing overheating.
2. Description of the Relevant Art
The frequency of a microprocessor clock signal is an important determinant with respect to the overall performance of a computer system. In general, as the speed of a microprocessor clock signal increases, the time required to execute various instructions decreases. Thus, microprocessors which are capable of running at relatively high internal clock frequencies are desirable for high performance and computational intensive applications.
Unfortunately, the frequency at which a microprocessor clock signal may be driven is limited. In general, as the frequency of the microprocessor clock signal is increased, the amount of heat generated by the microprocessor circuit also increases. If the temperature of the microprocessor chip exceeds a certain threshold, failures may occur. To complicate matters further, the threshold temperature at which a failure may occur in a microprocessor typically depends upon the current operating frequency. Therefore, manufacturers typically rate a microprocessor to run at some predetermined maximum frequency during which the system is guaranteed to operate properly. This predetermined maximum frequency is usually specified to account for worst-case conditions including worst-case ambient temperatures. However, since the conditions during which a microprocessor normally operates are typically better than worst-case, the rated predetermined maximum frequency may be significantly less than the frequency at which the microprocessor could actually be driven. As a result, the overall performance of the computer system may be unnecessarily degraded.